The role of Vitamin D in pregnancy, infancy, and lactation

The role of Vitamin D in pregnancy, infancy, and lactation

Well, vitamin D. To supplement, or not to supplement: that’s the question. Why, or why not? How much is enough? How much is too much?

At the most recent San Diego County Breastfeeding Coalition general meeting, the coalition’s vice president, Dr. James G. Murphy(MD, FAAP, FABM, IBCLC), answered it all.

So the short answer is: yes. Vitamin D (really a hormone) helps us to develop strong healthy bones and immune systems, and it does the same for our developing babies. Babies who don’t get enough vitamin D are more likely to develop rickets. Vitamin D also helps prevent major diseases including Parkinson’s disease and some cancers. However, “the average good American diet is very low in Vitamin D and no one can eat their way to Vitamin D sufficiency,” said Dr. Murphy, “We need supplement or sunshine!”

Exposing skin to the sun is a great way to get vitamin D. There was a time people enjoy sunbathing and kids love playing under the sunshine. But time has changed. Now everyone puts on sunscreen before getting dressed to protect their skin. Unfortunately, any sunscreen with SPF 8 or higher would completely prevent the body from making vitamin D. Today’s kids enjoy staying indoors and playing video games more than going outside in the sun.

There is not universal agreement among physicians regarding sun exposure. For those who desire to have sun exposure, 15 minutes in the sun belt (San Diego and south to the border all year long and most of the US in the peak summer months) between 10 AM and 2 PM with 40% of the body surface exposed to the sun without sunscreen and an adult will make 10,000 to 20,000 IU of vitamin D. Children make the amount they need in this same time period. After 15 minutes, apply sunscreen and enjoy the sun.

For those who wish to protect their skin with sunscreen all the time, supplementation with vitamin D is advisable. This is especially important for pregnant women and exclusively breastfed babies.

Supplementation with vitamin D is recommended for pregnant women because “the fetus takes what it needs from the mother if she has enough,” said Dr. Murphy, “Clinical manifestations of vitamin D deficiency are rare at birth but develop over the first month of life if mom is severely deficient.” Dr. Murphy also pointed out that insufficient vitamin D level is associated with a significant increase in the C-section rate and in the premature infant birth rate.

Babies need vitamin D, too. In 2008, American Academy of Pediatrics (AAP) recommended increasing the vitamin D daily dose to 400 IU from the previously recommend 200 IU, and to begin the supplementation in the first few days of life instead of at two month of age.

Depending on the formula milk, there are between 40 and 100 IU of Vitamin D per 100 calories in baby formula. Breast milk is, well, not artificially vitamin D fortified. Some formula companies use it to advertise that breast milk is flawed and formula is better. “Not true!” Dr. Murphy said it clear, “we wouldn’t need the supplement if we would get out in the sun. The problem is that we no longer get out in the sun, not that breast milk is not fortified. ”

Dr. Murphy also reminded breastfeeding mothers to get vitamin D supplementation. However, he said, “Mom is fortifying her breast milk by getting sun exposure. If mom gets the amount of sun to raise her vitamin D level to 70 ng/ml the breastfed infant will get enough vitamin D to reach at least a blood level of 40 ng/ml. Giving that infant 400 IU of Vit D daily would not then be needed.” He also recommended moms who maximize sun exposure for vitamin D check the infant’s blood level for vitamin D after several weeks to see if the ideal level has been achieved. If not, the appropriate supplement can be given until the level is at the desired level.

Not all organizations recommend the same amount of supplement each day. Currently vitamin D researchers in the Grass Roots Organization all recommends 4,000 IU/day for pregnant women and 1,000 IU/day for babies. Food and Nutrition Board recommends 600 IU/day for pregnant women and 400 IU/day for the babies.

Why is the confusion? “Food and Nutrition Board’s current ‘normal’ levels for vitamin D are based on studies done over 40 years ago on persons selected from the general population who appeared to have no apparent vitamin D related disorder,” explained Dr. Murphy. “Hence the lower value of the normal range of 10-15 ng/ml and the sufficient level of 30 ng/ml.”

Dr. Murphy recommends daily intake of 400 IU for the babies and 4,000 IU for the mothers.

Still, it is possible that we take or give the babies too much vitamin D. “Research found that high concentrations of vitamin D are toxic to rats,” said Dr. Murphy, “we want to give babies something good for them but we don’t want to give them too much.” So far no adverse side effects have been reported with doses less than 10,000 IU per day and blood levels less than 100 ng/mL.